Probabilistic load margin analysis considering stochastic wind power fluctuations

In this paper, probabilistic load margin analysis has been investigated under stochastic wind power fluctuations. First, a distributed bi-directional sweep method is examined for power flow computations when wind power generators are connected to a power grid. Both fixed-speed and doubly-fed induction generators are considered. Secondly, a novel direct method is proposed to estimate the load margin. In the proposed approach, a bordered system is applied to investigate an iterative method in order to reduce computational complexities. Moreover, the proposed novel direct method can be integrated to the bidirectional sweep method such that the distributed load margin prediction can be achieved. Finally, the probabilistic load margin analysis can be performed by integrating the load margin sensitivity, based on the distributed load margin estimation, and Gram-Charlier expansion method. Numerical demonstrations on several IEEE systems have demonstrated the effectiveness of the proposed method.